Slowly, slowly, autumn’s full blown color palette is creeping in. Right now it is: “Oh! Look at that tree!” Not a hillside of color but just a few leaves here and there turning with all their might to a spectacle of hues.

Changes in a leaf’s world, encourages slowing and stopping of photosynthesis which makes the leaf lose its chlorophyll and its green coloring. Depending on what compounds are most prominent in the leaf, determines its autumn color.

Carotenoids, and flavonoids both contribute yellows, while carotenoids also include oranges and reds in their repertoire. Both these compounds deminish, like the chlorophylls, but more slowly, allowing their colors to shine through autumn.

Another set of compounds, anthocyanins, a member of the flavonoids family, plays a part in some autumn leaf color. While carotenoids and flavonoids are present in the leaves during the growing season, anthocyanins are not. Autumn is the time for some leaves to manufacture this compound through increased sugar concentrations exposed to sunlight. This gives way to rich red, purple and magenta coloring in the those leaves.

Soon we’ll be at peak leaf season. I can’t wait.